Spinal retractor blade and related retractor device and method

Abstract

A spinal retractor blade and retractor device are provided. The retractor blade may include an optional straight first leg having an end joined to an end of a shank. The blade further includes a transition arcuately extending from the straight first leg by about 90° to 180° and terminating in a free end. A width of the transition is suitable for receiving a spinous process. Retractors in accordance with the invention may optionally include a pair of such blades, and the blades themselves may optionally include a second straight leg between the transition and the free end.

Having thus described the invention, it is now claimed: 
     
         1 . A retractor blade ( 115 ), comprising:
 a straight first leg ( 102 ) of the retractor blade having an end ( 104 ) joined to an end ( 118 ) of a shank ( 112 ), wherein the straight first leg is from zero cm to 6.0 cm in length, and wherein the shank is fixedly joined to a shank spreader;   a straight second leg ( 106 ) of the retractor blade having a free end ( 108 ), the straight second leg ( 106 ) oriented parallel to the straight first leg ( 102 ), wherein the straight second leg is from zero cm to 6.0 cm in length; and   a transition ( 114 ) from the straight first leg ( 102 ) to the straight second leg ( 106 ), wherein a width (w) between the straight first leg ( 102 ) and the straight second leg ( 106 ) is operable to receive a spinous process.   
     
     
         2 . The retractor blade of  claim 1 , wherein the end ( 104 ) of the straight first leg ( 102 ) is joined to the end ( 118 ) of the shank ( 112 ) so that a face ( 113 ) of the shank ( 112 ) does not extend beyond an inside face ( 103   i ) of the straight first leg ( 102 ). 
     
     
         3 . The retractor blade of  claim 1 , wherein the transition ( 114 ) is arcuate. 
     
     
         4 . The retractor blade of  claim 1 , wherein a length of the straight second leg ( 106 ) is determined by a length (L 1 ) of the blade exceeding a distance between a tangent line (T) of an apex ( 116 ) of the transition ( 114 ) and a parallel line drawn through an end of the straight second leg ( 106 ) most proximal to the tangent line (T) and an end of the straight first leg ( 102 ) most proximal to the tangent line (T), wherein the length of the straight second leg ( 106 ) does not exceed 6.0 cm. 
     
     
         5 . The retractor blade of  claim 1 , wherein the blade comprises a band ( 400 ) having a height (h) from about 4.0 cm to about 0.3 cm+/−10%. 
     
     
         6 . The retractor blade of  claim 1 , wherein the first straight leg ( 102 ) and the straight second leg ( 108 ) are spaced apart by the width (w) from about 0.3 cm to about 2.0 cm+/−10%. 
     
     
         7 . The retractor blade of  claim 1 , wherein the free end ( 108 ) of the straight second leg ( 106 ) is arcuate and defines an apex ( 402 ). 
     
     
         8 . A retractor blade, comprising:
 a straight first leg ( 102 ) of the retractor blade having an end ( 104 ) joined to an end ( 118 ) of a shank ( 112 ), wherein the shank is fixedly joined to a shank spreader; and   a transition ( 114 ) arcuately extending from the straight first leg ( 102 ) from about 90° to 180° and terminating in a free end ( 108 ), wherein a distance between the straight first leg ( 102 ) and the free end ( 108 ) is suitable for receiving a spinous process.   
     
     
         9 . The retractor blade of  claim 8 , wherein the end ( 104 ) of the straight first leg ( 102 ) is joined to a face ( 113 ) of the end ( 118 ) of the shank ( 112 ). 
     
     
         10 . The retractor blade of  claim 8 , wherein the transition ( 114 ) is arcuate. 
     
     
         11 . The retractor blade of  claim 8 , wherein the transition ( 114 ) is a circular segment having a radius between about 1.0 cm and about 0.15 cm+/−10%. 
     
     
         12 . The retractor blade of  claim 8 , wherein the blade comprises a band ( 400 ) having a height (h) from about 4.0 cm to about 0.3 cm+/−10%. 
     
     
         13 . The retractor blade of  claim 9 , wherein the free end ( 108 ) is arcuate and defines an apex ( 402 ). 
     
     
         14 . A spinal retractor, comprising:
 a first blade ( 115   f ) comprising:
 a straight first leg ( 102   f ) having an end ( 104   f ) joined to an end ( 118   f ) of a first shank ( 112   f ); 
 a straight second leg ( 106   f ) having a free end ( 108   f ), the straight second leg ( 106   f ) oriented parallel to the straight first leg ( 102   f ); and 
 a transition ( 114   f ) from the straight first leg ( 102   f ) to the straight second leg ( 106   f ), wherein a distance between the straight first leg ( 102   f ) and the straight second leg ( 106   f ) is suitable for receiving a spinous process; 
   a second shank ( 112   s ) opposing the first shank ( 112   f );   a shank spreader ( 501 ) in spreadable communication with the first shank ( 112   f ) and the second shank ( 112   s ); and   a ratchet ( 524 ) in ratcheting communication with the shank spreader ( 501 ).   
     
     
         15 . The spinal retractor of  claim 14 , further comprising:
 a second blade ( 115   s ) comprising:
 a straight first leg ( 102   s ) having an end ( 104   s ) joined to an end ( 118   s ) of a second shank ( 112   s ); 
 a straight second leg ( 106   s ) having a free end ( 108   s ), the straight second leg ( 106   s ) oriented parallel to the straight first leg ( 102   s ); and 
 a transition ( 114   s ) from the straight first leg ( 102   s ) to the straight second leg ( 106   s ), wherein a distance between the straight first leg ( 102   s ) and the straight second leg ( 106   s ) is suitable for receiving a spinous process. 
   
     
     
         16 . The spinal retractor of  claim 14 , wherein the shank spreader ( 701 ) comprises:
 a rack ( 730 ) fixedly joined to the first shank ( 112   f );   a carrier ( 735 ) fixedly joined to the second shank ( 112   s ), the carrier ( 735 ) slideably engaging the rack ( 730 ) through a pinion gear;   a knob ( 740 ) rotatably communicating with the pinion gear;   wherein the ratchet ( 724 ) is mounted to the carrier ( 735 ) and comprises a spring-loaded pawl ( 750 ) biased toward engagement of the rack ( 730 ), the pawl being configured to allow the carrier ( 735 ) to spread the first shank ( 112   f ) and the second shank ( 112   s ) while engaging the rack ( 730 ).   
     
     
         17 . The spinal retractor of  claim 14 , wherein the shank spreader comprises:
 a first member ( 510   f ) having a first handle ( 514   f ) and the first shank ( 112   f ), and having a first pivot joint ( 610   f ) between the first shank and the first handle; and   a second member ( 510   s ) having a second handle ( 514   s ) and a second shank ( 112   s ), and having a second pivot joint ( 610   s ) between the second handle ( 514   s ) and the second shank ( 112   s ).   
     
     
         18 . The spinal retractor of  claim 14 , wherein the first shank and the second shank each include a 90° turn. 
     
     
         19 . The spinal retractor of  claim 16 , wherein a handle ( 745 ) is linked to the knob ( 745 ) through a hinge ( 900 ). 
     
     
         20 . The spinal retractor of  claim 19 , wherein the handle ( 745 ) has a 90° range of motion about the hinge ( 900 ) relative to the knob ( 740 ). 
     
     
         21 . A method of vertebral retraction comprising the steps of:
 providing a first vertebra and a second vertebra adjacent to the first vertebra;   providing a spinal retractor, comprising:
 a first blade ( 115   f ) comprising:
 a straight first leg ( 102   f ) having an end ( 104   f ) joined to an end ( 118   f ) of a first shank ( 112   f ); 
 a straight second leg ( 106   f ) having a free end ( 108   f ), the straight second leg ( 106   f ) oriented parallel to the straight first leg ( 102   f ); and 
 a transition ( 114   f ) from the straight first leg ( 102   f ) to the straight second leg ( 106   f ), wherein a distance between the straight first leg ( 102   f ) and the straight second leg ( 106   f ) is suitable for receiving a spinous process; 
 
 a second shank ( 112   s ) opposing the first shank ( 112   f ); 
 a shank spreader ( 501 ) in spreadable communication with the first shank ( 112   f ) and the second shank ( 112   s ); and 
 a ratchet ( 524 ) in ratcheting communication with the shank spreader ( 501 ); 
   inserting the first blade between the first vertebra and the second vertebra;   actuating the shank spreader ( 501 ), causing the first blade to impinge a spinous process of the first vertebra; and   separating the first vertebra from the second vertebra by a predetermined amount.